For the Record: The Development of AMX 38
Source: http://yuripasholok.livejournal.com/4302315.html Hello everyone, Yuri Pasholok wrote an interesting post about the AMX 38, so sit down, have a cup of coffee or lunch and let’s have a look at it :) Apart from the companies Hotchkiss, Renault and FCM, AMX too participated in the program to create the next generation light tank for the French army. Atelier de Construction d’Issy-les-Moulineaux (AMX for short) was located south of Paris – it consisted of the former Renault tank plant, nationalized in 1936 and was the last company to enter the competition. Their tank project, later recieving the designation of AMX 38, was introduced in July 1937. The main idea behind the tank, as concieved by its designers during the project stage, was to increase the vehicle mobility, all the while keeping the light anti-shell armor (40mm) the same and the weight increase to a minimum. The first prototype weighed 13,5 tons (heavier than another project of the same program, FCM 36, by 1,15 tons) – this weight did later make some historians to in fact designate this tank as a medium vehicle. On the other hand, even with the 100 horsepower CLM diesel, assumed by the initial project, the dynamics of the AMX 38 only slightly surpassed the ones of the FCM 36 (power-to-weight ratio of 7,4 hp/t, compared to FCM’s 7,36). As for the built vehicle however, that one was equipped with a 130hp Aster engine, increasing the power-to-weight ratio to 9,62 hp/t. By that increase, this perspective tank surprassed its entire competition (Renault R 35 with its 7,73, Hotchkiss H 35 with its 7,07 and Hotchkiss H 39 with its 9,3 hp/t). The initial project counted on the installation of the 37mm SA18 gun (the same gun as FT-17, R 35, H 35 and FCM 36 had) and the first project variant (drawing 0-190 from 23.3.1939) assumed the installation of the APX-R turret. However, as early as June 1938, the turret was already replaced by a design of AMX’s own making, somewhat resembling the turret of FCM 36. The armament remained the same, as can be seen on the 0-190 drawing from 10.10.1938. AMX 38 with APX-R turret, drawing 0-190, 23.3.1939 Side view and suspension schematics, drawing 0-155, 13.6.1938. Hull, drawing 0-250, 3.4.1939 The first prototype of the AMX 38, built by the end of 1939, differed in a lot of ways from the initial project. The vehicle with the registration number W 0231 was equipped with a 37mm SA38 gun, paired with a 7,5mm MAC Mle.1931 machinegun. Like other French light tanks, AMX 38 had a “tail” mounted on the rear side of the hull, its purpose being to help the vehicle cross infantry trenches. The maximum speed of this vehicle was 25 km/h. This was not exactly the fastest vehicle on the battlefield, but on the other hand, it was completely sufficient for its intended role of supporting advancing infantry. In the end however, the prototype was not regarded as something, that should be mass-produced. AMX 38 stayed already behind other contemporary French tanks both in armor and armament. As such, the AMX company continued to work further and as early as in December 1939, a new vehicle began to take shape in the form of Char Leger Serie (something like “serial (mass-produced) light tank”). It’s sometimes being called AMX 39, but this designation is not very correct, as the vehicle continued to be developed well into the spring of 1940. Char Leger Serie, drawing 0-326, 11.12.1939 Improved AMX 38 hull, drawing 0-395, 14.3.1940 Gun, mounted in a modernized AMX 38 turret, drawing 0-339, 27.12.1939 The first significant difference between CLS and AMX 38 was the installation of the 47mm SA35 gun, replacing the older 37mm. With such a gun, the tank became significantly more dangerous to its enemies, including any German tank of that period. Additionally, the frontal turret and hull armor was increased to 60mm, making the standard German 37mm PaK practically useless against this vehicle. Of course, this reflected on the vehicle weight, that grew to 16,5 tons. The suspension also had to be reworked and the vehicle was planned to run with a more powerful engine (also Aster) of 160 horsepower. Thanks the the new engine, the power-to-weight ratio also grew a bit to 9,69 hp/t. The ending result was a light infantry tank, roughly equal to the British Valentine – not very fast, but well armored with a gun to match. True, the old flawed concept of one man turret, where the commander is also the gunner, loader and radioman would have impaired its effectiveness. But that’s all just a speculation, as no prototype of this improved AMX 38 was ever built.